Heat Capacity and Specific Heat Quiz

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Questions and Answers

What is the purpose of using a digital thermometer in the experiment?

The digital thermometer is used for its accuracy, measuring temperature changes to 0.1 °C.

How can the percentage error be reduced during the temperature change measurement?

Allowing a greater change in temperature will reduce the percentage error.

Describe the significance of insulating the metal block during the experiment.

Insulating the metal block minimizes heat loss or gain from the environment, ensuring accurate measurement of the heat absorbed by the metal.

What are the required conditions for the initial temperature of the metal in the experiment?

The initial temperature of the metal should be below room temperature to negate heat gain from the environment. Signup and view all the answers

Why is it important to crush the ice before adding it to the warm water in the calorimeter?

Crushing the ice allows it to melt more uniformly and ensures that all of the ice is at 0 °C before mixing. Signup and view all the answers

What is the difference between heat capacity and specific heat capacity?

Heat capacity measures the total heat required to raise the temperature of a body, while specific heat capacity measures the heat needed to raise 1 kg of a substance by 1 K. Signup and view all the answers

What is the specific heat capacity of water and why is it significant?

The specific heat capacity of water is 4180 J kg–1 K–1. This high value allows water to absorb and store large amounts of heat, making it effective for temperature regulation. Signup and view all the answers

Explain how storage heaters utilize specific heat capacity.

Storage heaters store heat in materials with high specific heat capacity, allowing them to absorb and retain heat during cheaper electricity rates and release it gradually throughout the day. Signup and view all the answers

In the sample problem, how is heat transferred between the hot copper and the water?

Heat is lost by the hot copper and gained by the water, reaching thermal equilibrium. Signup and view all the answers

Given the mass of copper and the specific heat capacity, how would you find the heat lost by the copper?

The heat lost by copper can be calculated using the formula: heat = mass × specific heat capacity × change in temperature. Signup and view all the answers

What role does insulation play in the operation of storage heaters?

Insulation in storage heaters minimizes heat loss, allowing stored energy to be released slowly throughout the day for efficient heating. Signup and view all the answers

How is the specific heat capacity of a substance essential in calorimetry experiments?

Specific heat capacity is crucial in calorimetry as it allows calculation of heat transfer during thermal exchanges between substances. Signup and view all the answers

What is the specific heat capacity of water in J kg–1 K–1?

4200 J kg–1 K–1 Signup and view all the answers

How does conduction differ from convection in heat transfer?

Conduction transfers heat through direct contact between particles, while convection involves the movement of fluid due to temperature-induced density differences. Signup and view all the answers

What do good thermal conductors have in common?

They facilitate the transfer of heat through the movement of energy between adjacent particles. Signup and view all the answers

What is the U-value a measure of?

The U-value quantifies the amount of heat energy conducted per second through 1 m² of a structure for a temperature difference of 1 K. Signup and view all the answers

Describe how solar heating systems typically work.

Solar heating systems use solar thermal collectors to heat water, which then rises to a tank, driven by convection, as cooler water replaces it from below. Signup and view all the answers

What is the importance of trapped air in insulation materials?

Trapped air enhances insulation because it is a poor conductor of heat, reducing heat loss. Signup and view all the answers

How is heat transferred by radiation, and what types of surfaces radiate heat more effectively?

Heat is transferred by electromagnetic waves, with dark surfaces radiating and absorbing heat more effectively than bright, shiny ones. Signup and view all the answers

Explain the role of convection currents in domestic hot water systems.

Convection currents help circulate hot water, allowing heated water at the top of the tank to flow out, ensuring efficient heating in the home. Signup and view all the answers

What factors determine the specific latent heat of fusion of ice?

It is determined by the amount of energy required to change ice into water without changing its temperature. Signup and view all the answers

Calculate the energy absorbed by 5000 kg of water when heated to increase its temperature by 70 K.

The energy absorbed is 1,471,000 J (or 1.47 MJ). Signup and view all the answers

What is the definition of heat capacity?

Heat capacity is the amount of heat energy required to raise the temperature of a given quantity of a substance by 1 K. Signup and view all the answers

Define specific heat capacity.

Specific heat capacity is the amount of heat required to raise the temperature of 1 kg of a substance by 1 K. Signup and view all the answers

What is the highest temperature achieved when 50 stones at 280 °C are added to 750 litres of water at 4 °C?

The highest temperature reached is approximately 113.1 °C. Signup and view all the answers

Suggest one improvement for the design of a fulacht fiadh for better efficiency.

Using insulated walls for the pit to reduce heat loss to the environment would improve efficiency. Signup and view all the answers

Explain how a heat pump operates.

A heat pump transfers heat from a cooler area to a warmer area by compressing the refrigerant vapor and thus raising its temperature. Signup and view all the answers

What are two desirable properties of a fluid used in a heat pump?

The fluid should have a high specific latent heat of vaporization and a low boiling point. Signup and view all the answers

Calculate the mass of the fluid that has evaporated from a heat pump if it removes 12 kJ from inside the refrigerator.

The mass of the evaporated fluid is 2.6 kg. Signup and view all the answers

If the volume of a refrigerator is 0.6 m³, how can the heat pump be used to cool this space?

The heat pump cools the refrigerator by absorbing heat from the air and releasing it outside, reducing the temperature inside. Signup and view all the answers

Why does the temperature of an athlete reduce when she perspires?

The temperature reduces because perspiration evaporates from the skin, which absorbs heat and cools the body. Signup and view all the answers

What is the average energy falling on an area of 5 m² of ground in Ireland in one minute, given the solar constant is $1.2 \times 10^2 W m^{-2}$?

The average energy is $36,000 J$ calculated as $1.2 \times 10^2 W m^{-2} \times 5 m^2 \times 60 s$. Signup and view all the answers

How much energy is lost through a double-glazed window with a U-value of 2.8 W m² K⁻¹, an area of 3.0 m², and a temperature difference of 9 °C over one hour?

The energy lost is $75.84 \text{ kJ}$ calculated as $2.8 W m^{-2} \times 3.0 m^2 \times 9 K \times 3600 s$. Signup and view all the answers

Distinguish between conduction, convection, and radiation as methods of heat transfer.

Conduction is heat transfer through direct contact, convection involves fluid movement carrying heat, and radiation is heat transfer through electromagnetic waves. Signup and view all the answers

Explain the term solar constant.

The solar constant is the amount of solar electromagnetic energy received per unit area at the outer edge of Earth's atmosphere, approximately $1361 W m^{-2}$. Signup and view all the answers

What observational conclusion could a student make from an experiment investigating heat transfer through water with a piece of aluminum?

The student would observe that the water's temperature increases as the aluminum loses heat. Signup and view all the answers

What role does insulation play in the heat transfer experiments described?

Insulation minimizes heat loss or gain between the system and the environment, ensuring accurate measurements. Signup and view all the answers

Why is it important to ensure the initial temperature of the water is below room temperature in the experiments?

This ensures that heat gained from the environment does not affect the accuracy of the experiment. Signup and view all the answers

How can one use the specific heat capacity of materials to calculate energy changes in heat transfer experiments?

By using the formula $Q = mc\Delta T$, where $Q$ is energy, $m$ is mass, $c$ is specific heat capacity, and $\Delta T$ is the temperature change. Signup and view all the answers

What precautions should be taken to ensure the accuracy of thermal measurements in calorimetry experiments?

Precautions include proper insulation, quick transfer of hot materials, and precise measurement tools. Signup and view all the answers

Flashcards

Specific Heat Capacity

The amount of heat energy required to raise the temperature of 1 kg of a substance by 1 K.

Heat Capacity

The amount of heat energy required to raise the temperature of a body by 1 K.

What is the principle behind storage heaters?

The ability of a material to store heat energy. Materials with high specific heat capacity can store large amounts of energy with minimal temperature change.